Non-volatile memory (NVM) devices are in general memory devices that retain, or store, data even when not powered. Presently, NVM devices are utilized in a wide range of applications including, for example, smart cards, microcontrollers (MCU), mobile phones, digital cameras, memory cards, and other applications where power is not always available, power is frequently interrupted, or lower power usage is required. Typical NVM devices include, for example, Erasable and Programmable Read Only Memory (EPROM) devices, Electrically Erasable and Programmable Read Only Memory (EEPROM) devices and flash memory.
Random access memory (RAM) device, such as resistive RAM (ReRAM or RRAM), is a type of NVM device. RAM devices tend to use lower energy consumption with increased performance when compared to conventional memory devices. RAM devices may have a cross-point cell configuration in which parallel bit lines are crossed by perpendicular word lines with the switching material placed between word line and bit line at every cross point. This architecture, however, can lead to a large “sneak” parasitic current flowing through non-selected memory cells via neighboring cells, which may result in incorrect reading of the selected cell or undesired writing to unselected cells.
Accordingly, there is a need for a new design of memory cells of RAM devices, and a manufacturing method thereof, to address and avoids the issue of sneak path.